2 Answers

Low voltage to your starter, measure your battery voltage if it isn't at
least 12.8 volts have it recharged and tested, it it test good reinstall it
and do voltage drop test on your cables, make sure the connection are
clean and corrosion free. After it starts test the alternator output, it
should be around 14.2 to 14.7 volts.

I have changed the fuel pump fuel filter and camshaft position sensor, I can drive it for a few days the all of a sudden drive somewhere turn the truck off go to start it and it wont start it has been...